Perinatal Mortality and Stillbirth Definitions
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Direct answer
Perinatal mortality covers stillbirths and early neonatal deaths, and its rate is expressed per 1000 total births. Under the WHO classification, the perinatal period runs from 22 completed weeks of gestation to seven completed days after birth. Stillbirth cut-offs vary between textbooks and national sources, so the definition used should always be stated.
What you must remember
- Perinatal period: From 22 completed weeks of gestation to seven completed days after birth, as classified by WHO.
- Stillbirth: Fetal death with no signs of life; WHO international-comparison and Indian survey (SRS, NFHS) convention is 28 completed weeks or about 1000 g, although ICD counts from 22 weeks.
- Early neonatal death: Death of a live-born baby within the first seven completed days of life.
- Perinatal mortality rate: Stillbirths plus early neonatal deaths, divided by total births and multiplied by 1000.
- Denominator: Total births means live births plus stillbirths, the WHO and Dutta convention; some Indian PSM texts divide by live births, so follow the formula stated in the question.
- Neonatal mortality: Death within the first 28 days of life, a wider measure that is not included in the perinatal rate.
A five-step calculation
Worked example: 985 live births, 15 stillbirths and 5 early neonatal deaths give 1000 total births and a rate of (15 + 5) divided by 1000, multiplied by 1000, which is 20 per 1000. Calculation questions follow the same five steps.
- Count total births: Add live births and stillbirths for the same period and place.
- Count stillbirths: Include fetal deaths at or beyond the chosen gestational or weight cut-off.
- Count early neonatal deaths: Include only deaths of live-born babies within the first seven completed days.
- Add the two death groups: Sum stillbirths and early neonatal deaths to form the numerator.
- Scale the result: Divide by total births, multiply by 1000, and state the cut-off that was used.
Most errors come from using live births as the denominator or from adding late neonatal deaths, so each step should be checked before the final figure is given.
Hospital audits use the same definitions, so changing the stillbirth cut-off part-way through a series makes trends hard to interpret. Stating the cut-off in every report keeps comparisons valid.
Where the exam tries to catch you
Perinatal questions usually test the time window, the denominator and the stillbirth cut-off.
- Trap: Including deaths between day 8 and day 28 in perinatal mortality Correct: Only early neonatal deaths in the first seven completed days count, and later deaths belong to neonatal mortality.
- Trap: Using live births as the denominator Correct: The standard WHO denominator is total births, live plus stillbirths, though some PSM texts use live births, so read the question's formula.
- Trap: Assuming one universal stillbirth cut-off Correct: Definitions vary between sources, so the chosen gestation or weight cut-off should be stated when rates are compared.
Frequently asked questions
Which deaths make up the perinatal mortality rate?
Perinatal mortality includes stillbirths and early neonatal deaths, meaning deaths within the first seven completed days after live birth. Deaths after seven days are excluded from the perinatal rate. The rate is expressed per 1000 total births.
How is the perinatal mortality rate calculated?
The rate is stillbirths plus early neonatal deaths, divided by total births (live births plus stillbirths), multiplied by 1000. The denominator is total births rather than live births alone. Consistent definitions are essential when comparing hospitals.
What gestation defines a stillbirth under WHO-based criteria?
Many WHO-based references define stillbirth as fetal death at 28 completed weeks or more, or birth weight of 1000 g or more, with no signs of life. Other sources use earlier cut-offs. The chosen definition should be stated whenever rates are reported.
How is early neonatal death different from neonatal death?
Early neonatal death occurs within the first seven completed days of life, while neonatal death covers the first 28 days. Perinatal mortality uses only early neonatal deaths. The distinction is often tested in calculation questions.